Double-length jaw system for electrosurgical instrument

ABSTRACT

An electrosurgical forceps includes a handle having a shaft extending therefrom defining a longitudinal axis. The handle is selectively movable to translate movement of the shaft along the longitudinal axis to actuate a pair of laterally spaced first and second jaw members pivotably connected to a distal end of the shaft. The first and second jaw members are moveable from an open position, wherein the first and second jaw members are in spaced relation relative to a stationary jaw member, to a closed position wherein the first and second jaw members cooperate with the stationary jaw member to grasp tissue therebetween. Each of the jaw members is adapted to connect to an electrosurgical energy source to conduct energy through tissue grasped therebetween to effect a tissue seal.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/834,703, filed on Mar. 15, 2013, which claims the benefit ofand priority to U.S. Provisional Application Ser. No. 61/664,492, filedon Jun. 26, 2012, the entire contents of each of which are incorporatedherein by reference.

BACKGROUND

1. Technical Field

The following disclosure relates to an apparatus, system, and method forperforming an electrosurgical procedure and, more particularly, to anapparatus, system and method that utilizes energy to seal and/or dividetissue.

2. Description of Related Art

Electrosurgical apparatuses (e.g., electrosurgical forceps) are wellknown in the medical arts and typically include a handle, a shaft, andan end effector assembly operatively coupled to a distal end of theshaft that is configured to manipulate tissue (e.g., grasp and sealtissue). Electrosurgical forceps utilize both mechanical clamping actionand electrical energy to effect hemostasis by heating the tissue andblood vessels to coagulate, cauterize, seal, cut, desiccate, and/orfulgurate tissue

As an alternative to open electrosurgical forceps for use with opensurgical procedures, many modern surgeons use endoscopes and endoscopicelectrosurgical apparatus (e.g., endoscopic forceps) or laparoscopicforceps for remotely accessing organs through smaller, puncture-likeincisions. As a direct result thereof, patients tend to benefit fromless scarring, fewer infections, shorter hospital stays, less pain, lessrestriction of activity, and reduced healing time. Typically, theforceps are inserted into the patient through one or more various typesof cannulas or access ports (typically having an opening that rangesfrom about five millimeters to about twelve millimeters) that has beenmade with a trocar. As such, smaller cannulas are typically moredesirable relative to larger cannulas. Forceps that are configured foruse with small cannulas (e.g., cannulas less than five millimeters) maypresent design challenges for a manufacturer of electrosurgicalinstruments.

SUMMARY

According to one aspect of the present disclosure, an electrosurgicalforceps is provided. The electrosurgical forceps includes a handlehaving a shaft extending therefrom defining a longitudinal axis. Thehandle is selectively movable to translate movement of the shaft alongthe longitudinal axis to actuate a pair of laterally spaced first andsecond jaw members pivotably connected to a distal end of the shaft. Thefirst and second jaw members are moveable from an open position, whereinthe first and second jaw members are in spaced relation relative to astationary jaw member, to a closed position wherein the first and secondjaw members cooperate with the stationary jaw member to grasp tissuetherebetween. Each of the jaw members is adapted to connect to anelectrosurgical energy source to conduct energy through tissue graspedtherebetween to effect a tissue seal.

Alternatively or in addition, an inner shaft is axially disposed withinthe shaft and fixedly coupled to the stationary jaw member. The shaftmay be configured to slide over the inner shaft upon movement along thelongitudinal axis.

Alternatively or in addition, at least one of the first and second jawmembers may be pivotally coupled to a distal end of the stationary jawmember.

Alternatively or in addition, movement of the shaft along thelongitudinal axis may be configured to pivot the first and second jawmembers substantially simultaneously between the open and closedpositions.

Alternatively or in addition, distal movement of the shaft may beconfigured to actuate the jaw members to the closed position.

Alternatively or in addition, proximal movement of the shaft may beconfigured to actuate the jaw members to the open position.

Alternatively or in addition, the first and second jaw members may bedisposed vertically offset from the stationary jaw member such that atleast a portion of each of the first and second jaw memberssubstantially aligns in vertical registration with at least a portion ofthe stationary jaw member when the jaw members are in the closedposition.

Alternatively or in addition, an electrically conductive tissue sealingplate may be operatively coupled to each of the jaw members. Theelectrically conductive tissue sealing plates may be adapted to connectto the electrosurgical energy source to conduct energy through tissuegrasped between the jaw members to effect the tissue seal.

Alternatively or in addition, the first and second jaw members may bedisposed vertically offset from the stationary jaw member such that atleast a portion of the electrically conductive tissue sealing plates ofeach of the first and second jaw members substantially aligns invertical registration with at least a portion of the electricallyconductive tissue sealing plate of the stationary jaw member when thejaw members are in the closed position.

Alternatively or in addition, at least one of the first and second jawmembers may be generally L-shaped.

Alternatively or in addition, at least one of the first and second jawmembers may be pivotally coupled to the shaft via a linkage. The linkagemay be pivotally coupled to the shaft and configured to control aclosing angle of the at least one jaw member relative to the stationaryjaw member such that the at least one jaw member is disposedsubstantially parallel to the stationary jaw member when the jaw membersare in the closed position.

According to a further aspect of the present disclosure, anelectrosurgical forceps is provided. The electrosurgical forcepsincludes a handle having a shaft extending therefrom defining alongitudinal axis. The handle is selectively movable to translatemovement of the shaft along the longitudinal axis to actuate a pair oflaterally spaced first and second jaw members pivotably connected to adistal end of the shaft. The first and second jaw members are moveablefrom an open position, wherein the first and second jaw members are inspaced relation relative to an opposing jaw member, to a closed positionwherein the first and second jaw members cooperate with the opposing jawmember to grasp tissue therebetween. The first and second jaw membersare vertically offset from the opposing jaw member such that at least aportion of each of the first and second jaw members substantially alignsin vertical registration with at least a portion of the opposing jawmember. Each of the jaw members is adapted to connect to anelectrosurgical energy source to conduct energy through tissue graspedtherebetween to effect a tissue seal.

Alternatively or in addition, proximal movement of the shaft may beconfigured to rotate the first jaw member counter clock-wise away fromthe opposing jaw member and the second jaw member clock-wise away fromthe opposing jaw member.

Alternatively or in addition, distal movement of the shaft may beconfigured to rotate the first jaw member clock-wise toward the opposingjaw member and the second jaw member counter clock-wise toward theopposing jaw member.

Alternatively or in addition, the opposing jaw member may be stationary.

Alternatively or in addition, an inner sleeve may be axially disposedwithin the shaft and fixedly coupled to the opposing jaw member. Theshaft may be configured to slide over the inner shaft upon movementalong the longitudinal axis.

Alternatively or in addition, the opposing jaw member may form a distalend of the inner sleeve.

According to a further aspect of the present disclosure, a method ofperforming an electrosurgical procedure is provided. The method includesthe step of providing an electrosurgical forceps. The electrosurgicalforceps includes a handle having a shaft extending therefrom defining alongitudinal axis. The handle is selectively movable to translatemovement of the shaft along the longitudinal axis to actuate a pair oflaterally spaced first and second jaw members pivotably connected to adistal end of the shaft. The first and second jaw members are moveablefrom an open position, wherein the first and second jaw members are inspaced relation relative to a stationary jaw member, to a closedposition wherein the first and second jaw members cooperate with thestationary jaw member to grasp tissue therebetween. Each of the jawmembers is adapted to connect to an electrosurgical energy source. Themethod also includes the steps of selectively moving the handle totranslate movement of the shaft along the longitudinal axis to move thefirst and second jaw members from the open position to the closedposition to grasp tissue therebetween and delivering electrosurgicalenergy from the electrosurgical energy source to each of the jaw membersto effect a tissue seal.

Alternatively or in addition, the selectively moving step may includerotating the first jaw member clock-wise toward the stationary jawmember and the second jaw member counter clock-wise toward thestationary jaw member.

Alternatively or in addition, the first and second jaw members may bevertically offset from the stationary jaw member such that at least aportion of each of the first and second jaw members substantially alignsin vertical registration with at least a portion of the stationary jawmember.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described hereinbelowwith references to the drawings, wherein:

FIG. 1 is a perspective view of an endoscopic bipolar forceps showing ahousing, a shaft, and an end effector assembly in accordance with anembodiment of the present disclosure;

FIG. 2A is a schematic, side elevational view of the end effectorassembly of FIG. 1 with the jaw members in open configuration;

FIG. 2B is a schematic, side elevational view of the end effectorassembly of FIG. 1 with the jaw members in a closed configuration;

FIG. 3A is a schematic, side elevational view of an end effectorassembly according to another embodiment of the present disclosure, withthe jaw members in an open configuration;

FIG. 3B is a schematic, side elevational view of the end effectorassembly of FIG. 3A, with the jaw members in a closed configuration; and

FIG. 4 is an enlarged, rear, perspective view of the end effectorassembly of FIG. 1 shown grasping tissue.

DETAILED DESCRIPTION

Detailed embodiments of the present disclosure are disclosed herein,however, the disclosed embodiments are merely examples of thedisclosure, which may be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure.

As noted above, it may prove useful in the arts to provide anelectrosurgical apparatus that is suitable for use during catheter-basedendoluminal procedures and/or for use with various access ports,including but not limited to those that are greater than and/or lessthan five millimeters. The present disclosure may be particularlyadvantageous for use with flexible-shafted instrument designs, such ascatheter-based designs used in endoluminal procedures. With this purposein mind, the present disclosure includes an electrosurgical forceps thatincludes jaw members associated with an end effector assembly of theelectrosurgical forceps. The jaw members are operably coupled to anelectrosurgical energy source and are each configured to conduct anelectrical potential (e.g., positive or negative) therethrough that maybe the same or opposite to that of the other jaw member(s) (e.g., in abipolar configuration). In some embodiments, a shaft mechanicallycooperates with a handle assembly and at least one of the jaw members tomove the jaw members between an open configuration to a closedconfiguration. In the closed configuration, the jaw members utilizetissue grasped therebetween to form a closed loop electrical circuitsuch that a desired tissue effect (e.g., tissue seal) may be achieved.

Turning now to FIG. 1, an embodiment of an endoscopic bipolar forceps 10is shown for use with various surgical procedures and generally includesa housing 20, a handle assembly 30, a rotating assembly 80, a triggerassembly 70, and an end effector assembly 100 that mutually cooperate tograsp, seal, and divide tubular vessels and vascular tissue. Althoughthe majority of the figure drawings depict a bipolar forceps 10 for usein connection with endoscopic surgical procedures, the presentdisclosure may be used for more traditional open surgical procedures.For the purposes herein, the forceps 10 is described in terms of anendoscopic instrument, however, it is contemplated that a version of theforceps for “open” procedures may also include the same or similaroperating components and features as described below.

In the drawings and in the descriptions that follow, the term“proximal”, as is traditional, will refer to the end of the forceps 10that is closer to the user, while the term “distal” will refer to theend that is farther from the user.

Forceps 10 includes a shaft 12 that has a distal end 14 configured tomechanically engage the end effector assembly 100 and a proximal end 16that mechanically engages the housing 20. Proximal end 16 of shaft 12 isreceived within housing 20 and appropriate mechanical and electricalconnections relating thereto are established.

Forceps 10 includes an electrosurgical cable 310 that connects theforceps 10 to a source of electrosurgical energy, e.g., a generator (notshown). One such source of electrosurgical energy is described incommonly-owned U.S. Pat. No. 6,033,399 entitled “ELECTROSURGICALGENERATOR WITH ADAPTIVE POWER CONTROL”. Cable 310 is internally dividedinto several cable leads (not shown) that each transmit electricalpotentials through their respective feed paths through the forceps 10 tothe end effector assembly 100.

For a more detailed description of handle assembly 30, movable handle40, rotating assembly 80, and electrosurgical cable 310 (includingline-feed configurations and/or connections) reference is made tocommonly owned Patent Publication No. 2003/0229344, filed on Feb. 20,2003, entitled VESSEL SEALER AND DIVIDER AND METHOD OF MANUFACTURING THESAME.

Handle assembly 30 includes a fixed handle 50 and a movable handle 40.Fixed handle 50 is integrally associated with housing 20 and handle 40is movable relative to fixed handle 50 as explained in more detail belowwith respect to the operation of the forceps 10. Rotating assembly 80 isoperatively connected to the housing 20 and is rotatable in eitherdirection about a longitudinal axis “X-X” (See FIG. 1).

End effector assembly 100 is attached to the distal end 14 of shaft 12and includes a pair of laterally spaced jaw members 110 a and 110 b thatare configured to pivot relative to an opposing stationary jaw member120. Movable handle 40 is operatively connected to shaft 12, whichmechanically cooperate to impart movement of the jaw members 110 a and110 b from an open position (FIG. 2A) wherein the jaw members 110 a and110 b are disposed in spaced relation relative to the opposingstationary jaw member 120, to a clamping or closed position (FIG. 2B)wherein the jaw members 110 a and 110 b cooperate with stationary jawmember 120 to grasp tissue therebetween for sealing purposes. Duringmovement of jaw members 110 a, 110 b from the open position to theclosed position, jaw members 110 a, 110 b pivot toward each other, i.e.,jaw member 110 a pivots clock-wise toward stationary jaw member 120 andjaw member 110 b pivots counter clock-wise toward stationary jaw member120. During movement of jaw members 110 a, 110 b from the closedposition to the open position, jaw members 110 a, 110 b pivot away fromeach other, i.e., jaw member 110 a pivots counter clock-wise away fromstationary jaw member 120 and jaw member 110 b pivots clock-wise awayfrom stationary jaw member 120. With this purpose in mind, forceps 10may include any suitable number of configurations, components,mechanical connections, and/or components (e.g., gears, links, springs,rods, etc.), and/or electro-mechanical connections, configurations,and/or components such that forceps 10 may function as intended.

In some embodiments, forceps 10 may be configured such that it isre-usable or such that it is fully or partially disposable dependingupon a particular purpose or to achieve a particular result. Forexample, end effector assembly 100 may be selectively and releasablyengageable with the distal end 14 of shaft 12 and/or the proximal end 16of shaft 12 may be selectively and releasably engageable with thehousing 20 and the handle assembly 30. In either of these two instances,the forceps 10 would be considered “partially disposable” or“reposable”, e.g., a new or different end effector assembly 100 (or endeffector assembly 100 and shaft 12) selectively replaces the old endeffector assembly 100 as needed.

As best shown in FIGS. 2A and 2B, jaw members 110 a, 110 b also includea jaw housing 116 a, 116 b, respectively, that has a respectiveinsulative substrate or insulator 114 a, 114 b and an electricallyconducive sealing surface 112 a, 112 b. Insulators 114 a, 114 b areconfigured to secure the electrically conductive sealing surfaces 112 a,112 b, respectively, to respective jaw housings 116 a, 116 b. This maybe accomplished by overmolding insulators 114 a, 114 b about jawhousings 116 a, 116 b, respectively, or by other suitable methods suchas using adhesives.

Stationary jaw member 120 includes similar elements to jaw members 110a, 110 b such as a jaw housing 126 having an insulator 124 and anelectrically conductive sealing surface 122 that is secured to the jawhousing 126 by the insulator 124. This may be accomplished, for example,by overmolding insulator 124 about jaw housing 126, or by other suitablemethods such as using adhesives.

The illustrated embodiment of FIGS. 2A and 2B is illustrative only inthat any one or more of jaw members 110 a, 110 b or 120 may beconfigured to be devoid of an insulating substrate 114 a, 114 b or 124.For example, in some embodiments, jaw members 110 a, 110 b may includeinsulating substrate 114 a, 114 b, respectively, and stationary jawmember 120 may be configured such that insulating substrate 124 isremoved and/or end effector assembly 100 may be manufactured such thatstationary jaw member 120 does not include an insulating substrate. Theinsulators 114 a, 114 b, 124, electrically conductive sealing surfaces112, 112 b, 122, and the jaw housings 116, 126 are configured to limitand/or reduce many of the known undesirable effects related to tissuesealing, e.g., flashover, thermal spread, and stray current dissipation.In other embodiments, the jaw members 110 a, 110 b, and 120 may bemanufactured from a ceramic-like material and the electricallyconductive surfaces 112 a, 112 b, and 122 are coated onto theceramic-like jaw members 110 a, 110 b, and 120, respectively.

The end effector assembly 100 may be designed as a unilateral assembly,i.e., stationary jaw member 120 is fixed relative to the shaft 12 andjaw members 110 a and 110 b pivot about respective pivot pins 103 a and103 b relative to stationary jaw member 120 to grasp tissue, or as abilateral assembly, i.e., jaw members 110 a, 110 b and stationary jawmember 120 pivot relative to each other to grasp tissue. In someembodiments and as will be discussed in further detail below, jawmembers 110 a, 110 b are laterally spaced apart along a distallyextended portion 13 of the distal end 14 of shaft 12 and are rotatableabout pivot pins 103 a and 103 b, respectively, such that jaw members110 a, 110 b pivot relative to stationary jaw member 120 for purposes ofgrasping tissue therebetween. In the illustrated embodiment of FIGS. 2Aand 2B, jaw member 110 b is generally linear in configuration and jawmember 110 a is generally L-shaped.

With continued reference to FIGS. 2A and 2B, end effector assembly 100includes one stationary jaw member 120 mounted in fixed relation to aninner shaft 60 that is coaxially disposed within the shaft 12. In someembodiments, stationary jaw member 120 is monolithically formed withinner shaft 60 such that stationary jaw member 120 forms a distal end ofinner shaft 60. Jaw member 110 b is pivotally coupled by way of pivotpin 103 b to a linkage 140 that, in turn, couples to a distal end 108 ofthe extended portion 13 of shaft 12 via a pivot pin 105. Stationary jawmember 120 includes a generally L-shaped distal end 123 to which jawmember 110 b is pivotally coupled via a pivot pin 107.

Jaw member 110 a is pivotally coupled to a proximal portion of thestationary jaw member 120 via pivot pin 103 a. As discussed above, jawmember 110 a is generally L-shaped in the illustrated embodiment ofFIGS. 2A and 2B. A linkage 130 is operably coupled by way of a pivot pin101 to or substantially proximate to the vertex of the generallyL-shaped jaw member 110 a and, in turn, couples to the shaft 12 via apivot pin 102 to effectively couple jaw member 110 a to the shaft 12.

Shaft 12 is slidingly disposed about inner shaft 60 and is remotelyoperable by handle assembly 30 to translate movement of shaft 12relative to inner shaft 60 along longitudinal axis “X-X”. In order toopen end effector assembly 100, shaft 12 is withdrawn or pulled in aproximal direction (see FIG. 2A), by actuating movable handle 40relative to fixed handle 50. In order to close end effector assembly100, shaft 12 is pushed or moved in a distal direction (see FIG. 2B), byactuating movable handle 40 relative to fixed handle 50. By way ofexample, moving shaft 12 in the proximal direction, as depicted in FIG.2A, may be effected by squeezing movable handle 40 toward stationaryhandle 50. In this scenario, moving shaft 12 in the distal direction, asdepicted in FIG. 2B, may be effected by approximating movable handle 40away from stationary handle 50. In some embodiments, the configurationdescribed in the above scenario may be reversed, e.g., squeezing movablehandle 40 will move shaft 12 in the distal direction and approximatingmovable handle 40 away from stationary handle 50 will move shaft 12 inthe proximal direction.

Jaw members 110 a and 110 b are actuated into the closed position bysliding the shaft 12 axially over inner shaft 60 in the distal directionsuch that jaw member 110 a pivots about pivot pins 101 and 103 a towardstationary jaw member 120 and jaw member 110 b rotates about pivot pins103 b and 107 toward stationary jaw member 120, as depicted in FIG. 2B.In this manner, pushing shaft 12 distally closes jaw members 110 a and110 b substantially simultaneously and, in conjunction with sealingsurface 122, creates an effective tissue sealing area at least the sizeof tissue sealing surface 122. Counter clock-wise rotation of jaw member110 b about pivot pins 103 b and 107 is aided by counter clock-wiserotation of linkage 140 about pivot pin 105 as shaft 12 is sliddistally. More specifically, as linkage 140 rotates counter clock-wiseabout pivot pin 105, the angle of closure of jaw member 110 b relativeto stationary jaw member 120 is decreased so that as jaw member 110 bmoves into the closed position such that sealing surface 112 b isdisposed in a substantially parallel configuration relative to sealingsurface 122, as depicted in FIG. 2B.

Jaw members 110 a and 110 b are actuated into the open position bysliding the shaft 12 axially over inner shaft 60 in the proximaldirection such that jaw member 110 a pivots about pivot pins 101 and 103a away from stationary jaw member 120 and jaw member 110 b rotates aboutpivot pins 103 b and 107 away from stationary jaw member 120, asdepicted in FIG. 2B. In this manner, pulling shaft 12 proximally opensjaw members 110 a and 110 b substantially simultaneously. Clock-wiserotation of jaw member 110 b about pivot pins 103 b and 107 is aided byclock-wise rotation of linkage 140 about pivot pin 105 as shaft 12 isslid proximally.

As described above, the dual pivoting of jaw members 110 a, 110 brelative to stationary jaw member 120 operates to increase (e.g.,double) the effective tissue sealing area between jaw members 110 a, 110b and stationary jaw member 120. In some embodiments, sealing surfaces112 a and 112 b may each be substantially half of the length of sealingsurface 122 such that upon closure of jaw members 110 a and 110 b,sealing surfaces 112 a, 112 b are substantially equal to the length ofsealing surface 122 to provide a relatively larger effective tissuesealing area with respect to a conventional pair of opposing tissuegrasping jaw members. In this manner, stationary jaw member 120 may bemanufactured with increased length relative to conventional jaw membersto create a larger and/or longer effective tissue sealing surfacerelative to sealing surfaces of conventional surgical forceps.

As best shown in FIG. 2B, jaw members 110 a and 110 b are disposedgenerally adjacent to stationary jaw member 120 or are at leastpartially vertically offset from stationary jaw member 120. However,when jaw members 110 a, 110 b are in the closed position, as shown inFIG. 2B, at least a portion of jaw members 110 a, 110 b overlaps orsubstantially aligns in vertical registration with at least a portion ofstationary jaw member 120. In some embodiments, tissue sealing surfaces110 a, 110 b and 122 are disposed on respective jaw members 110 a, 110b, and 120 in such a way so that when jaw members 110 a, 110 b are inthe closed position, as shown in FIG. 2B, at least a portion of tissuesealing surfaces 112 a and 112 b overlaps or substantially aligns invertical registration with tissue sealing surface 122 to form theeffective tissue sealing surface area between jaw members 110 a, 110 band stationary jaw member 120.

Turning now to FIGS. 3A and 3B, another embodiment of forceps 10including an end effector assembly 200, in accordance with the presentdisclosure, is shown and described. End effector assembly 200 mayinclude some, if not all, of the features and elements associated withend effector assembly 100 and as described above with reference to FIGS.2A and 2B. End effector assembly 200 is substantially as described abovewith respect to end effector assembly 100 of FIGS. 1, 2A, and 2B andwill only be described to the extent necessary to disclose thedifferences between the embodiments. While end effector assembly 200 isshown as having a unilateral jaw member arrangement, end effectorassembly 200 may, in certain embodiments, have a bilateral jaw memberarrangement.

As shown in FIGS. 3A and 3B, end effector assembly 200 includes opposingjaw members 110 a and 110 b having electrically conductive tissuesealing surfaces 112 a and 112 b, respectively. Jaw members 110 a and110 b cooperate with stationary jaw member 120 to grasp tissuetherebetween, as substantially described above with respect to theembodiment of FIGS. 2A and 2B. In the illustrated embodiment of FIGS. 2Aand 2B, jaw member 110 b is generally linear in configuration. The jawmember 110 b shown in FIGS. 3A and 3B differs from jaw member 110 bshown in FIGS. 2A and 2B in that the jaw member 110 b of FIGS. 3A and 3Bis generally L-shaped similar to jaw member 110 a of FIGS. 2A and 2B.

With continued reference to FIGS. 3A and 3B, the generally L-shapedconfiguration of jaw member 110 b causes the angle of closure of jawmember 110 b relative to stationary jaw member 120 to increase such thatjaw member 110 b is permitted to rotate about pivot pins 103 b and 107toward stationary jaw member 120 so that sealing surface 112 b ispositioned substantially parallel to sealing surface 120 when jaw member110 b is in the closed position, as depicted in FIG. 3B.

In some embodiments, either or both of jaw members 110 a and 110 b mayinclude a cam slot configuration (not shown) to facilitate actuation ofjaw members 110 a and 110 b. In this scenario, for example, jaw member110 a may include a cam slot in which pivot pin 102 translates relativeto the shaft 12 upon rotational movement of jaw member 110 a about pivotpin 103 a to improve the opening and closing motion of jaw member 110 a.The location where pivot pin 102 couples to the shaft 12 may also bemodified from the illustrated embodiments to improve the opening andclosing motion of jaw member 110 a. Likewise, jaw member 110 b mayinclude a cam slot in which pivot pin 105 and/or 103 btranslates uponrotational movement of jaw member 110 b about pivot pin 107. In someembodiments, although not explicitly shown in the illustratedembodiments, the above described cam slot configuration may replacelinkage 140 such that pivot pin 105 connects the distal end 108 of theextended portion 13 to jaw member 110 b and translates within a cam slotupon rotational movement of jaw member 110 b. The location where pivotpin 105 couples to the extended portion 13 may also be modified from theillustrated embodiments to improve the opening and closing motion of jawmember 110 b.

FIG. 4 shows forceps 10 grasping tissue. As the handle 40 is squeezed,jaw members 110 a and 110 b are approximated toward stationary jawmember 120 to a clamped or closed position about tissue. Once jawsmembers 110 a and 110 b are fully compressed about the tissue, forceps10 is now ready for selective application of electrosurgical energy andsubsequent separation of the tissue. By controlling the intensity,frequency, and duration of the electrosurgical energy applied to tissue,the operator can either cauterize, coagulate/desiccate, seal, cut,and/or simply reduce or slow bleeding. Two mechanical factors play animportant role in determining the resulting thickness of the sealedtissue and effectiveness of the seal, i.e., the pressure applied betweenopposing jaw members 110 a, 110 b and 120 and the gap distance “G”between the opposing sealing surfaces 112 a, 112 b and 122 of the jawmembers 110 a, 110 b and 120 during the sealing process.

At least one jaw member (e.g., stationary jaw member 120) may include astop member (not shown) extending a predetermined distance from thesealing surface 112 a, 112 b, or 122 that limits the movement ofopposing jaw members 110 a, 110 b relative to stationary jaw member 120.The predetermined distance may be according to the specific materialproperties (e.g., compressive strength, thermal expansion, etc.) of thestop member(s) to yield a consistent and accurate gap distance “G”during sealing (FIG. 4). In some embodiments, the gap distance betweenopposing sealing surfaces 112 a, 112 b and 122 during sealing rangesfrom about 0.001 inches to about 0.006 inches and, in other embodiments,between about 0.002 and about 0.003 inches. Several suitable thermalspraying techniques may be utilized including, for example, depositing abroad range of heat resistant and insulative materials on varioussurfaces to create stop members for controlling the gap distance betweenelectrically conductive surfaces 112 a, 112 b and 122.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

1-20. (canceled)
 21. An end effector assembly, comprising: a stationaryjaw member defining a longitudinal axis and having a proximal end and adistal end; a first jaw member disposed adjacent the proximal end of thestationary jaw member; and a second jaw member disposed adjacent thedistal end of the stationary jaw member and laterally spaced from thefirst jaw member along the longitudinal axis of the stationary jawmember, wherein the first and second jaw members are each configured tomove relative to the stationary jaw member between an open position,wherein at least a portion of each of the first and second jaw membersare spaced relative to the stationary jaw member, and a closed position,wherein the first and second jaw members cooperate with the stationaryjaw member to grasp tissue between the stationary jaw and at least oneof the first or second jaws.
 22. The end effector assembly according toclaim 21, wherein the first jaw member is pivotably coupled to theproximal end of the stationary jaw member, and the second jaw member ispivotably coupled to the distal end of the stationary jaw member. 23.The end effector assembly according to claim 22, wherein upon movementof the first and second jaw members from the open position to the closedposition, the first jaw member pivots relative to the proximal end ofthe stationary jaw member in a first rotational direction, and thesecond jaw member pivots relative to the distal end of the stationaryjaw member in a second rotational direction, opposite the firstrotational direction.
 24. The end effector assembly according to claim21, further comprising: a first linkage having a first end pivotablycoupled to the first jaw member and a second end configured to bepivotably coupled to a shaft; and a second linkage having a first endpivotably coupled to the second jaw member and a second end configuredto be pivotably coupled to the shaft.
 25. The end effector assemblyaccording to claim 21, wherein the distal end of the stationary jawmember is L-shaped.
 26. The end effector assembly according to claim 21,wherein at least one of the first jaw member or the second jaw member isL-shaped.
 27. The end effector assembly according to claim 21, whereinin the open position, the first and second jaw members are substantiallyperpendicular to the stationary jaw member, and in the closed position,the first and second jaw members are substantially parallel with thestationary jaw member.
 28. The end effector assembly according to claim21, wherein the stationary jaw member includes: a jaw housing; aninsulator disposed on the jaw housing; and a conductive sealing surfacedisposed on the insulator.
 29. The end effector assembly according toclaim 28, wherein the first and second jaw members each have aconductive sealing surface having a first length, the conductive sealingsurface of the stationary jaw member having a second lengthsubstantially equal to twice the first length.
 30. An end effectorassembly, comprising: a stationary jaw member having a proximal end anda distal end; a first jaw member having a first end pivotably coupled tothe proximal end of the stationary jaw member and a second end; and asecond jaw member having a first end pivotably coupled to the distal endof the stationary jaw member and a second end, the first ends of thefirst and second jaw members being longitudinally spaced from oneanother along the stationary jaw member.
 31. The end effector assemblyaccording to claim 30, wherein the first and second jaw members areconfigured to be movable relative to the stationary jaw member betweenan open position, wherein the second ends of the first and second jawmembers are spaced relative to the stationary jaw member, and a closedposition, wherein the second ends of the first and second jaw membersapproximate the stationary jaw member.
 32. The end effector assemblyaccording to claim 31, wherein upon movement of the first and second jawmembers from the open position to the closed position, the first jawmember pivots relative to the proximal end of the stationary jaw memberin a first rotational direction, and the second jaw member pivotsrelative to the distal end of the stationary jaw member in a secondrotational direction, opposite the first rotational direction.
 33. Theend effector assembly according to claim 31, wherein in the openposition, the first and second jaw members are substantiallyperpendicular to the stationary jaw member, and in the closed position,the first and second jaw members are substantially parallel with thestationary jaw member.
 34. The end effector assembly according to claim30, further comprising: a first linkage having a first end pivotablycoupled to the first jaw member and a second end configured to bepivotably coupled to a shaft; and a second linkage having a first endpivotably coupled to the second jaw member and a second end configuredto be pivotably coupled to the shaft.
 35. The end effector assemblyaccording to claim 30, wherein the distal end of the stationary jawmember is L-shaped.
 36. The end effector assembly according to claim 30,wherein at least one of the first jaw member or the second jaw member isL-shaped.
 37. The end effector assembly according to claim 30, whereinthe stationary jaw member includes: a jaw housing; an insulator disposedon the jaw housing; and a conductive sealing surface disposed on theinsulator.
 38. The end effector assembly according to claim 37, whereinthe first and second jaw members each have a conductive sealing surfacehaving a first length, the conductive sealing surface of the stationaryjaw member having a second length substantially equal to twice the firstlength.